Casting an eye on the education of children, from whence I can make a judgment of my own, I observe they are instructed in religious matters before they can reason about them, and consequently that all such instruction is nothing else but filling the tender mind of a child with prejudices.

Where the people are well educated, the art of piloting a state is best learned from the writings of Plato.

Many things, for aught I know, may exist, whereof neither I nor any other man hath or can have any idea or notion whatsoever.

But the velocities of the velocities - the second, third, fourth, and fifth velocities, etc. - exceed, if I mistake not, all human understanding.

All men have opinions, but few think.

I might as well doubt of my own being, as of the being of those things I actually see and feel.

Of all men living [priests] are our greatest enemies. If it were possible, they would extinguish the very light of nature, turn the world into a dungeon, and keep mankind for ever in chains and darkness.